try:
    height_weight_input = input("请输入身高(米)和体重(公斤),用逗号隔开:")
    height,weight = map(float, height_weight_input.split(','))
    bmi = weight / pow (height, 2)
    print("BMI 数值为: {:.2f}".format(bmi))
    if bmi < 18.5:
        print("偏瘦")
    elif 18.5 <= bmi < 25:
        print("正常")
    elif 25 <= bmi < 30:
        print("偏胖")
    else:
        print("肥胖")
except ValueError:
    print("输入错误，请输入有效的数字，身高和体重用逗号隔开。")
